1. Field of the Invention
This invention relates to a new type cam suitable for use in a parallel piston engine. More specifically the cam is adapted to fit into a circular arrangement of pistons and cylinders around a mainshaft, which pistons act in concert to effect rotation of the mainshaft by virtue of pressure exerted on the sinusoidal surfaces of the cam lobe encircling the mainshaft. Still more specifically the cam surface is specially designed to avoid friction and binding between the bearings and cam surface.
2. State of the Prior Art
Various types of engines for developing mechanical power, such as for propelling vehicles, have been proposed and are in use. The most commonly used is the internal combustion engine. However, in spite of their widespread use, there are a number of disadvantages in the types of engines used, namely vibration, low efficiency, pollution, etc.
Vibration is generally due to the type of arrangement of the pistons with relation to the drive shaft, which in combination with poor timing, unequal power distribution, etc., is very inefficient in eliminating vibration although much has been done in absorbing vibration or otherwise eliminating its transmission to the passenger-riding portion of an automobile.
Since rotary engines may have pistons equally spaced around the mainshaft through which power is transmitted, it is conceivable that such engines might have less problems with vibration.
A number of patents have been cited in parent applications. These include U.S. Pat. Nos. 1,197,896; 1,229,009; 1,351,365; 1,352,985; 1,487,338; 1,802,902; 1,867,504; 1,971,121; 2,027,076; 2,050,127; 2,237,621; 2,237,989; 2,243,817; 2,243,818; 2,243,819; 2,284,319; 2,966,899; 3,225,659; 3,456,630; 3,726,183; and 4,090,478; British Patent No. 251,607 (1926); French Pat. No. 861,625 (1939); Swiss Pat. No. 58,995 (1911); and German Patents Nos. 17,074 (1881) and 137,280 (1901). Some of these patents describe engines in which pistons are arranged parallel to a mainshaft which is driven by a cam rotated by the action of the pistons. However none of these have met with commercial success. The lack of commercial success of the engines shown in these patents is believed to be due to a number of defects therein in which the designs do not provide for centerline thrust between the pistons, bearings and cam surface and the cam surfaces are not designed to avoid friction and binding between the bearings and the cam surfaces. Some of these references describe methods of making sinusoidal cams by tracing or duplicating a master cam. The difficulties and problems of making an original or master cam are described by above cited U.S. Pat. No. 3,726,183. The method of making an original or master sinusoidal cam is described in pages 693-710 of the 21st edition of "Machinery's Handbook" published 1981 by Industrial Press Company of 200 Madison Avenue, New York, N.Y. 10157. As will be noted this is a complicated, cumbersome method.